I tend to get my story ideas from other story ideas, though I'd say the prose/fiction I write is usually inspired by media other than prose. Sometimes I'll see a movie or a TV show that sparks something, or sometimes I'll hear a line in a song (or just read song lyrics in general) that'll spark an idea. I don't know that I get too many ideas from other books--more like I learn other writing strategies from them.

I mostly get inspiration from current affairs and past affairs (no, the news variety you dirty bastards ) , and from books i've read, films ive seen, my imagination, various bullshit on the internet, asking 'what if' type questions , and from just pantsing stuff out and seeing where it goes

for example my current wip is based loosely on the C&C recon teams in vietnam (about which ive read various books) but the action is set in a post viral apocalyptic England (inspired by asking what if about things like swine flu and ebola), and a lot of the action takes place along the wall which seperates the remaining civilisation from chaos - broadly inspired by various stuff ive read about hadrians wall in roman times. Various plot points come from stuff i've done or friends who are still in the army have done, and jokes etc come from personal experience or stuff i've heard etc , or corrupting common sayings (e,g rather than tell his new recruits that the enemy of my enemy is my friend, Blade tells them "the enemy of our enemy is a dodgy bastard I don't much trust either"

ATEOD i suspect most writers mix all sorts of experience, research, and bullshit up and see what comes out, in a sort of put it together and what have we got, bippity boppity boooks ... fashion

I don't get much inspiration from topics though, i find them too glutinous, i prefer a toblerone